Many aircraft and other vehicles are being built with smaller, shorter seat backrests for vehicle occupants. In order to support the head, neck, and back of vehicle occupants in seats with shorter backrests, headrest extension assemblies may be advantageous. The added support of headrest extension assemblies becomes increasingly important in emergency situations, such as crashes, where supporting the head and neck of vehicle occupants is of utmost importance. However, as seat backrests become shorter, headrest extension assemblies become larger and heavier. Increasingly heavy headrest extension assemblies may be difficult for vehicle occupants to move and adjust, particularly from a seated position. Consequently, there is a need in the art for headrest and/or backrest assemblies that cure one or more shortfalls identified above.